Simulating ice-shelf extent using damage mechanics

• Published in: Journal of Glaciology
• Main Authors: Samuel B. Kachuck, Morgan Whitcomb, Jeremy N. Bassis, Daniel F. Martin, Stephen F. Price
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2022
• Subjects: Iceberg calving; ice physics; ice-shelf break-up; ice-sheet modeling; ice shelves; Environmental sciences; GE1-350; Meteorology. Climatology; QC851-999; Amery; Amery Ice Shelf; Antarctic; Drygalski; Drygalski Ice Tongue; Erebus Glacier; Erebus Glacier Tongue; Ross Ice Shelf; The Antarctic; Antarc*; Ice Sheet; Ice Shelf; Ice Shelves; Iceberg*; Journal of Glaciology
• Online Access: https://doi.org/10.1017/jog.2022.12; https://doaj.org/article/f2b4392495ad4a0fb49bfb2a3936afee

Inaccurate representations of iceberg calving from ice shelves are a large source of uncertainty in mass-loss projections from the Antarctic ice sheet. Here, we address this limitation by implementing and testing a continuum damage-mechanics model in a continental scale ice-sheet model. The damage-mechanics formulation, based on a linear stability analysis and subsequent long-wavelength approximation of crevasses that evolve in a viscous medium, links damage evolution to climate forcing and the large-scale stresses within an ice shelf. We incorporate this model into the BISICLES ice-sheet model and test it by applying it to idealized (1) ice tongues, for which we present analytical solutions and (2) buttressed ice-shelf geometries. Our simulations show that the model reproduces the large disparity in lengths of ice shelves with geometries and melt rates broadly similar to those of four Antarctic ice shelves: Erebus Glacier Tongue (length ~ 13 km), the unembayed portion of Drygalski Ice Tongue (~ 65 km), the Amery Ice Shelf (~ 350 km) and the Ross Ice Shelf (~ 500 km). These results demonstrate that our simple continuum model holds promise for constraining realistic ice-shelf extents in large-scale ice-sheet models in a computationally tractable manner.